Lateral Space Research Articles

On the role of turbulent large-scale streaks in generating sediment ridges

The role of turbulent large-scale streaks or large-scale motions in forming subaqueous sediment ridges on an initially flat sediment bed is investigated with the aid of particle resolved direct numerical simulations of open channel flow at bulk Reynolds numbers up to 9500. The regular arrangement of quasi-streamwise ridges and troughs at a characteristic spanwise spacing between 1 and 1.5 times the mean fluid height is found to be a consequence of the spanwise organisation of turbulence in large-scale streamwise velocity streaks. Ridges predominantly appear in regions of weaker erosion below large-scale low-speed streaks and vice versa for troughs. The interaction between the dynamics of the large-scale streaks in the bulk flow and the evolution of sediment ridges on the sediment bed is best described as ‘top-down’ process, as the arrangement of the sediment bedforms is seen to adapt to changes in the outer flow with a time delay of several bulk time units. The observed ‘top-down’ interaction between the outer flow and the bed agrees fairly well with the conceptual model on causality in canonical channel flows proposed by Jiménez (J. Fluid Mech., vol. 842, 2018, P1, § 5.6). Mean secondary currents of Prandtl's second kind of comparable intensity and lateral spacing are found over developed sediment ridges and in single-phase smooth-wall channels alike in averages over ${O}(10)$ bulk time units. This indicates that the secondary flow commonly observed together with sediment ridges is the statistical footprint of the regularly organised large-scale streaks.

Lateral Capsular Stabilization in Lateral Meniscal Allograft Transplantation.

Background:Stabilization of the lateral capsule to the tibial plateau may decrease midbody extrusion after lateral meniscal allograft transplantation (MAT). However, there is a paucity of literature reporting on postoperative magnetic resonance imaging (MRI) findings after lateral capsular stabilization (LCS) at the time of lateral MAT.Purpose/Hypothesis:The purpose was to describe MRI findings after LCS and compare postoperative extrusion between isolated lateral MAT and lateral MAT with LCS. It was hypothesized that allograft extrusion would be reduced after MAT with LCS but that the stabilized capsule would increase the risk of tears to the capsule or allograft.Study Design:Cohort study; Level of evidence, 3.Methods:Included were patients who underwent lateral MAT with 6-month follow-up MRI. Concomitant LCS was performed for patients with redundant lateral capsule displaced from the lateral tibial plateau as evident on coronal MRI or arthroscopic examination (MAT+LCS group); otherwise, patients underwent MAT only (isolated MAT group). The Lysholm score, Tegner score, and lateral joint space on radiographs were compared between the 2 groups at 2 years postoperatively, and the stabilized lateral capsule and allograft were evaluated using 6-month follow-up MRI. Extrusion, rotation, and position of the allograft bridge were compared between the 2 groups. Regression analysis was performed to identify factors predictive of degree of extrusion.Results:There were 10 patients in the MAT+LCS group and 13 patients in the isolated MAT group. No significant differences were found between groups in preoperative patient characteristics or postoperative Lysholm score, Tegner score, lateral joint space, or MRI parameters. Postoperative extrusion was not related to obliquity angle, position of the bony bridge, or presence of LCS. In the MAT+LCS group, 1 patient showed a tear of the lateral capsule and a radial tear of the allograft, and 3 patients had a meniscocapsular separation at the midbody of the allograft. In the isolated MAT group, 1 patient had a peripheral tear at the midbody, but there was no tear of the allograft in the other patients.Conclusion:LCS did not decrease extrusion of lateral meniscal transplantation, but it can lead to increased risk for graft or capsule tear.

Proximal Fibular Osteotomy for Medial Joint Osteoarthritis of the Knee: A Prospective Cohort Study.

Background and objectiveOsteoarthritis (OA) is a polyarticular disease that most commonly afflicts the knee joint. Established operative treatment options for medial joint OA of the knee include high tibial osteotomy, unicompartmental knee arthroplasty, and total knee arthroplasty. Proximal fibular osteotomy (PFO) is a relatively new procedure for treating medial joint OA of the knee. The objective of this study was to describe the functional and radiological outcomes at one year in patients undergoing PFO for medial joint OA of the knee.Materials and methodsThe study included 21 patients with medial joint OA of the knee who underwent PFO. Visual analog scale (VAS) score, medial to lateral knee joint space ratio (ML ratio), Kellgren-Lawrence (KL) grade, and the American Knee Society Score (AKSS) (clinical and functional) were recorded preoperatively. VAS score, ML ratio, and AKSS (clinical and functional) were documented again at the three-month and one-year follow-ups.ResultsThe mean age of the patients was 58.85 ±6.94 years; 12 (57.1%) were female and nine (42.9%) were males. The mean VAS score for pain decreased from 7.86 ±0.66 at baseline to 5.14 ±1.15 at three months (p<0.001) and 3.78 ±1.26 at one year (p<0.001). The mean clinical AKSS was 56.49 ±6.95 at baseline, which increased to 63.41 ±6.20 at three months (p<0.001) and 72.71 ±9.87 at one year (p<0.001). The mean functional AKSS at baseline was 48.24 ±14.31, which increased to 60.10 ±14.81 at three months (p<0.001) and 71.46 ±15.18 at one year (p<0.001). The mean ML ratio at baseline was 0.33 ±0.19, which increased to 0.41 ±0.20 at three months (p<0.01) and 0.51 ±0.22 at one year (p<0.001).ConclusionIn patients who undergo PFO for OA of the knee, improvements in VAS score for pain, AKSS (functional and clinical), and ML ratio were observed to be maintained for a period of one year postoperatively.

Research on Mechanical Performance of Improved Low Vibration Track and Its Feasibility Analysis for Heavy-Haul Railway Applications

With the gradual increase of the cargo weight of heavy-haul trains, the traditional ballasted track with the accumulation of stone and ballast has been unable to meet its structural safety requirements. From the comparison of the three common ballastless tracks in China, it can be seen that the low-vibration track (LVT) has the advantages of reasonable structure, low cost, and easy maintenance. Therefore, the design and research of heavy-haul railways are focused on, and it is urgent to study the applicability of LVT in heavy-haul railways. Method: By improving the slope of the short side of the LVT support block, the support block has a better load bearing capacity, so as to achieve the purpose of bearing a larger axle load. Through 1:1 full-scale model test and finite element simulation, the static mechanical properties of Improved LVT (ILVT) and Traditional LVT (TLVT) are compared and analyzed. Result: Compared with TLVT, ILVT has smaller vertical displacement and track gauge changes when subjected to the same load. The proven and reliable finite element model also shows that ILVT’s load sharing is less affected. In the case of achieving the same deformation, ILVT can withstand greater vertical and lateral loads. Conclusions: Compared with the TLVT, the ILVT design can reduce the vertical displacement of the rail and the supporting block, better control the track subsidence, and improve the driving safety of the LVT. At the same time, ILVT improves the anti-overturning ability of the rail and support block under lateral load, reduces the expansion of the gauge and the lateral spacing of the support block, and improves the stability of the track structure. ILVT can also be considered for the weight of 40t and other large axle load, and has broad application prospects.

Mimics of carcinoma: pancytokeratin positive follicular dendritic cell sarcoma

Abstract Introduction/Objective Follicular dendritic cell sarcoma (FDC-S) is a malignant neoplasm of follicular dendritic cells that can present with variable morphology including epithelioid and spindle cell components. Given its morphological diversity, FDC-S can mimic neoplasms including poorly differentiated carcinomas. Here we present a rare case of FDC-S in which immunohistochemical staining for pancytokeratin was focally positive, potentially leading to an erroneous diagnosis if a full spectrum of immunohistochemical stains was not considered. Methods/Case Report A 34-year-old man presented with an enlarging left neck mass, night sweats and fatigue that began approximately three months ago. CT scan showed a 5.6 x 4.2 x 3.7 cm necrotic mass in the left upper lateral carotid space. Histologic examination of the incisional biopsy specimen demonstrated portions of soft tissue comprised of pleomorphic and plump spindle cells forming whorls with no discernable node architecture (Panels A-B). The tumor cells are large with oval nuclei, vesicular chromatin, distinct nucleoli, and a moderate amount of eosinophilic cytoplasm. Occasional binucleated and multinucleated tumor cells, rare tumor cells with nuclear pseudoinclusions and atypical mitotic figures, and focal necrosis are identified. Scattered small mature lymphocytes are present. By immunohistochemistry, tumor cells are positive for pancytokeratin (focal) (Panel C), CD21 (panel D), CD23 (panel E), D2-40 (panel F), CD35 and clusterin, and negative for CD3, CD20, CD30, CD45, ALK-1, EMA, PAX5, PDL1 and S100 stains. The overall morphology and immunostaining pattern are compatible with follicular dendritic cell (FDC) sarcoma. Results (if a Case Study enter NA) NA Conclusion FDC sarcoma rarely occurs as the solitary mass in the head and neck region. The unusual focal positivity for pancytokeratin highlights the importance of comprehensive immunohistochemistry stains to confirm the diagnosis of FDC sarcoma since this case is focally positive for pancytokeratin, mimicking other neoplasms such as poorly differentiated carcinomas

The application of contrast‐enhanced CT combined with Image navigation in retrieval of displaced tooth: A case report and literature review

AbstractBackgroundThe displacement of a tooth to deep facial spaces is a rare but serious complication. The lateral pharyngeal space contains important structures such as the internal carotid artery, internal jugular vein and cranial nerves. To remove a displaced tooth from the lateral pharyngeal space is a difficult and high‐risk procedure because of the narrow space and the structures inside it.Material and methodsThis is a report of the application of contrast‐enhanced CT combined with image navigation in retrieval of a displaced tooth from the lateral pharyngeal space.ResultsThe displaced tooth was removed successfully. Satisfactory wound healing was achieved, without postoperative complications.ConclusionThis case report illustrates the importance of a method to optimize navigation, reduce damage to important anatomical structures, and provide a more precise and minimally invasive surgical procedure.

Biomechanical analysis of sitting-up movement of knee joint after robot-assisted unicompartmental knee arthroplasty

To investigate the effect of Navio robot-assisted unicompartmental knee arthroplasty (UKA) on the biomechanics of knee joint during sitting-up movement, and to determine whether UKA can maintain the biomechanical characteristics of knee joint. The clinical data of 8 patients with medial compartment osteoarthritis treated with medial fixed platform of Navio robot-assisted UKA between January 2018 and January 2019 and had the complete follow-up data were retrospectively analyzed. There were 4 males and 4 females; the age ranged from 58 to 67 years, with an average of 62.3 years. The disease duration was 6-18 months, with an average of 13 months. The varus deformity ranged from 4° to 6°, with an average of 5°; the knee flexion range of motion was 0°-130°, with an average of 110°. All patients had no extension limitation. The imaging data of bilateral knees during sitting-up movement were collected by biplane C-arm X-ray machine at 3 weeks before operation and 7 months after operation. The three-dimensional models of femur and tibia were established by dual-energy CT scanning, and the three-dimensional models of femur and tibia were matched and synchronized with the femur and tibia in X-ray film by automatic matching tracer software. The biomechanical parameters of femur and tibia were measured, including internal rotation/external rotation, varus/valgus, forward/backward displacement of medial and lateral tibia contact center, and lateral compartment joint space. Eight patients were followed up 5-7 months, with an average of 6.4 months. In the comparison of the affected side before and after operation, except for the difference of varus/valgus which was significant ( t=4.959, P=0.002), the differences in other indicators was not significant ( P>0.05). There were significant differences in varus/valgus and internal rotation/external rotation between healthy and affected sides at 3 weeks before operation ( P<0.05), and the differences in other indicators was not significant ( P>0.05). At 7 months after operation, the difference in the forward and backward displacement of medial tibia contact center was significant ( t=3.798, P=0.007), and the differences in other indicators was not significant ( P>0.05). UKA can effectively correct the varus and valgus of the knee joint, and restore the rotational biomechanical characteristics of the affected knee joint. It does not affect the establishment of the lateral compartment joint space, but the medial and lateral tibia contact center still changes.

Go Wide before Closing in: A Safe Approach to Minimally Invasive Hysterectomy for a Large Broad Ligament Leiomyoma

<h3>Study Objective</h3> Demonstrate total laparoscopic hysterectomy technique for a large broad ligament leiomyoma. <h3>Design</h3> Surgical video <h3>Setting</h3> Tertiary-care operating room using standard equipment for laparoscopic surgery and four 5 mm trocars, a 30-degree laparoscope, and bipolar sealing device. <h3>Patients or Participants</h3> A 47-year-old female with pelvic pressure, bulkiness and occasional right sided pelvic pain found to have a twenty-centimeter broad ligament leiomyoma. <h3>Interventions</h3> She desired to have a definitive surgical treatment. She underwent total laparoscopic hysterectomy, bilateral salpingectomy, and cystoscopy. <h3>Measurements and Main Results</h3> Although leiomyomas are the most common benign tumors of the female pelvis, broad ligament leiomyomas are rare. Broad ligament is the most common extrauterine site for the occurrence of leiomyoma with the incidence of <1%. Laparoscopy revealed a large pelvic mass extending through the right board ligament and retroperitoneal space consistent with radiographic imaging. The surgery began on the left side by ligating the blood supply to the uterus in the retroperitoneal space, disconnecting the suspensory ligaments of the uterus. On the right side, the round ligament transected and the incision extended parallel to the infundibulopelvic ligament to enter the right retroperitoneum. The uterine artery was ligated at its origin and the mass was carefully enucleated out of lateral pararectal space while preserving the branches of hypogastric nerve. We utilized the colpotomy cup to demarcate our anatomical landmark and complete the hysterectomy. Pathology revealed benign leiomyoma and reported no malignancy in uterus, cervix and bilateral fallopian tubes. <h3>Conclusion</h3> Board ligament leiomyomas may pose significant anatomical distortion and adhesive disease making minimally invasive surgical approach very challenging. Anatomic knowledge is imperative to safely gain access to the retroperitoneal space, ligate the blood supplies at its origin, preserve crucial pelvic nerves and excise these masses without increasing morbidity to the patient.

Digital radiographic measurement of tibial and femoral condylar articular surface asymmetry and knee joint space

Introduction: Knee joint is a major weight bearing synovial joint. In frontal radiograph we can see asymmetrical joint spaces between femoral and tibial components due to asymmetric wear and tear. Articular surfaces of tibial and femoral condyles are also asymmetrical. In frontal radiograph, the tibial condylar articular surface can be seen projected outside laterally or medially with respect to lateral or medial femoral condyle. Objectives: To measure tibial and femoral articular surface asymmetry. Measurement of tibial and femoral joint space. Materials and Methods: This epidemiological study was conducted in Orthopaedic outpatient department (OPD) of Ramakrishna Mission Seva Pratishthan Kolkata. Total 350 patients were selected. Frontal standing radiograph of both knees with 100% magnification were obtained. Tibial condylar asymmetry and joint spaces were measured with calliper. Height and weight measurements were also done. Statistical analysis was done. Results: In right knee 96% patients lateral tibial condyle was projected outside with respect to femoral condyle. In 9.3% patients’ medial tibial condyle was outside. In left knee 92.6% patients lateral tibial condyle was outside and 15.7% patients’ medial tibial condyle was outside. In right knee lateral joint space was mean + sd= 4.45 + 1.06, medial joint space mean + sd= 1.70 + 94. In left knee lateral joint space was mean + sd= 4.59 + 1.00, medial joint space was mean + sd= 1.76 + 1.00. Conclusion: In this study, in most of the patients we found tibial and femoral articular surface asymmetry mainly in lateral side. In joint space measurement, we found that medial joint space was less than lateral joint space in both knees.

The influence of tidal turbine arrangement on the wake interaction in shallow water

The arrangement of tidal turbines in the tidal farm is known to be complicated due to the resistance to the tidal flow which causes the flow to be channeled around the individual devices. To successfully implement the tidal turbine, the wake interaction between the device and its implication needs to be fully understood. Typically, the wake interaction in the array depends on the arrangement and spacing between the device in the array. In this study, a numerical analysis is conducted through the use of Computational Fluid Dynamic (CFD) approach to investigate the influence of the array setup in shallow water application and to propose a suitable array layout for possible application in Malaysia. The numerical analysis is carried out with 2 combination sets of lateral and longitudinal spacing covering 15 turbines in staggered and squared array layout. Hypothetical ‘actuator’ disk and ‘actuator’ cylinder model are used to represent the Horizontal axis turbine (HATT) and Vertical axis turbine (VATT) respectively. The results showed that the VATT model has faster wake recovery and obeys the definition of the far wake. Staggered arrays with bigger spacing are preferable for application in shallow water due to the low probability of wake merging between the rows.

The experimental study on damaged square columns strengthened by reinforcement mesh steel fiber

Eight common reinforced concrete columns were damaged by different sizes loads. The damaged reinforced concrete columns were strengthened by reinforcement mesh steel fiber. Three identical test pieces were made to explore the dispersion of the reinforcement method. The axial compression experiment was researched by factor of mortar types, damage degree, the lateral and longitudinal spacing. The formula of the axial bearing capacity of damaged square columns were strengthened by reinforcement mesh steel fiber was proposed. The calculated values agreed well with the experimental results. The test results showed that the damaged square columns were strengthened by reinforcement mesh steel fiber was an effective reinforcement method. This method was less discrete and can not only improve the ultimate bearing capacity, cracking load ductility and anti-cracking ability, but also the mechanical properties and failure mode can be effectively improved.

Flow Characteristics of a Circular Cylinder behind an Impinging Airfoil Near Wake with Different Lateral Spacing

A computational model is formulated to investigate the unsteady flow characteristics of a circular cylinder behind an impinging airfoil near-wake at Re=200. The distance between the airfoil trailing edge and the downstream cylinder axis is fixed at 1.5D where D is the diameter of circular cylinder and the lateral spacing is varied from 5 to 5 so as to numerically investigate the effect of lateral spacing on the flow characteristics. The present work is concerned on the following aspects: the general flow patterns, the vortex shedding frequency, force fluctuations and spectra, as well as the effect of lateral spacing on the flow features at low Reynolds number and small axial spacing. The calculated flow pattern and its comparison with the visualization by Laser-Induced Fluorescence (LIF) technique are conducted. It is determined that three regimes can be defined in terms of H/D, where H is the distance between the cylinder center and the line extended from the airfoil leading edge to trailing edge. And four kinds of typical flow pattern associated with the three regimes can be identified accordingly. It is interesting to find that both the fluctuations of lift and drag forces on the circular cylinder exhibit symmetric features centered at H/D=0 and the dump distribution of C′SUBD/SUB is found as well.

Effect of Installation Depths and Emitter Spacing on Water Productivity and Yield of a Subsurface Drip Irrigated Sugarcane

In the present investigation the effect of drip lateral installation depths and emitter spacing on sugarcane crop water productivity and yield was studied by installing laterals at 15, 20 and 30 cm depths from surface, while the emitters were spaced at 50, 60 and 75 cm. A factorial experiment in the form of randomized complete block design was carried out at the Sugarcane Research and Training Institute of Khuzestan in South-West of Iran. Sugarcane quantity specifications results showed there was significant difference between treatments in terms of drip emitter spacing and lateral installation depths and their interactions at 1% probability level. Similar trends were also observed in case of quality traits of sugarcane. Investigating the water productivity index for sugarcane and sugar yield it showed that treatments were significant in terms of the space between emitters at 1% probability level. The maximum sugarcane yield was observed in the treatment with a space between emitters of 50 cm, and 20 cm of installation depth. At 60 cm space the emitters of 60 cm and the installation depth of application of 20 cm, the highest water productivity was obtained, reaching 7.18 and 0.87 kg/m3 for produced sugarcane and sugar respectively.

Biomimetic Rotary Tillage Blade Design for Reduced Torque and Energy Requirement.

A rotary cultivator is a primary cultivating machine in many countries. However, it is always challenged by high operating torque and power requirement. To address this issue, biomimetic rotary tillage blades were designed in this study for reduced torque and energy requirement based on the geometric characteristics (GC) of five fore claws of mole rats, including the contour curves of the five claw tips (GC-1) and the structural characteristics of the multiclaw combination (GC-2). Herein, the optimal blade was selected by considering three factors: (1) the ratio (r) of claw width to lateral spacing, (2) the inclined angle (θ) of the multiclaw combination, and (3) the rotary speed (n) through the soil bin tests. The results showed that the order of influence of factors on torque was n, r, and θ; the optimal combination of factors with the minimal torque was r = 1.25, θ = 60°, and n = 240 rpm. Furthermore, the torque of the optimal blade (BB-1) was studied by comparing with a conventional (CB) and a reported optimal biomimetic blade (BB-2) in the soil bin at the rotary speed from 160 to 320 rpm. Results showed that BB-1 and BB-2 averagely reduced the torque by 13.99% and 3.74% compared with CB, respectively. The field experiment results also showed the excellent soil-cutting performance of BB-1 whose average torques were largely reduced by 17.00%, 16.88%, and 21.80% compared with CB at different rotary speeds, forward velocities, and tillage depths, respectively. It was found that the geometric structure of the five claws of mole rats could not only enhance the penetrating and sliding cutting performance of the cutting edge of BB-1 but also diminish the soil failure wedge for minimizing soil shear resistance of BB-1. Therefore, the GC of five fore claws of mole rats could inspire the development of efficient tillage or digging tools for reducing soil resistance and energy consumption.

Experimental investigation of the wake characteristics behind twin vertical axis turbines

Vertical axis wind and tidal turbines are a promising technology, well suited to harness kinetic energy from highly turbulent environments such as urban areas or rivers. The power density per occupied land area of two or three vertical axis rotors deployed in close proximity can notably exceed that of their horizontal axis counterparts. Using acoustic Doppler velocimetry, the three-dimensional wake developed downstream of standalone and twin vertical axis turbines of various shaft-to-shaft distances and rotational direction combinations was characterised in terms of mean velocity and turbulence statistics, with their impact on momentum recovery quantified. Results show that the wake hydrodynamics were more impacted by turbine rotational direction than lateral distance between devices for the range of lateral spacing considered. In the cases with turbines operating in a counter-rotating forward configuration, the wake mostly expanded laterally and attained the largest velocities that exceeded those in the single turbine case, with full momentum recovery at 5 turbine diameters downstream. The wake developed by the counter-rotating backward setup notably extended over the vertical direction, whilst devices rotating in the same direction featured the greatest lateral wake expansion with reduced velocities. Linear wake superposition of the single turbine wake provided a good representation of the mean velocity field behind twin-turbine setups. The presented results indicate that, in the design of twin-turbine arrays moving in counter-rotating forward direction, a lateral spacing of, at least, two turbine diameters should be kept as this allows the kinetic energy in the wake to be fully recovered by five turbine diameters downstream.

Reconstruction of Complex Lateral Skull Base Defects After Oral Cancer Resection With Individualized Anterolateral Thigh Flap.

ObjectivesComplex lateral skull base defects resulting from advanced or recurrent oral cancer resection are continuously challenging reconstructive surgeons. This study aimed to use reconstructive methods for lateral skull base defects, explore their feasibility, and evaluate the efficacy of defect reconstruction using anterolateral thigh (ALT) flaps.Patients and MethodsWe performed a retrospective case series of 37 patients who underwent lateral skull base defect reconstruction using the ALT/anteromedial thigh (AMT) flap between March 2016 and May 2021 at the Second Xiangya Hospital. The design and harvest of the flaps, methods for defect reconstruction, and reconstructive efficacy are described.ResultsOf the 37 patients, 3 were women and 34 were men, with a mean age of 51.7 years. Among the defects, 26 were through-and-through defects and were reconstructed using ALT chimeric flaps, double ALT flaps, folded ALT flap, combined ALT chimeric flaps and AMT flaps, or combined ALT chimeric flaps and pectoralis major flaps; the large lateral skull base dead spaces were filled with muscle tissues or fatty tissues. Postoperatively, 38 of the 39 ALT/AMT flaps survived completely, and the remaining flap experienced partial necrosis. Venous compromise occurred in one patient who was salvaged after operative exploration. Oral and maxillofacial wound infections occurred in two patients, salivary fistula in three patients, and thigh wound effusion in three patients. The wounds healed gradually in all patients after repeated dressing changes. Thirty-three patients were followed up for approximately 3–60 months; their oral functions and appearance were acceptable, and thigh motor dysfunction was not observed.ConclusionsWith the convenient flap design and muscle flap harvest, large and individualized tissue supply, feasible combination with other flaps, effective reduction or avoidance of wound complications, and acceptable donor site morbidity, the ALT flap is an appropriate choice for complex lateral skull base defect reconstruction.

Accuracy of MRI and X-Ray Measurement of Displacement Distance of Humeral Lateral Condyle Fractures.

ObjectiveTo investigate the accuracy of X‐ray and magnetic resonance imaging (MRI) measurements in evaluating the displacement of humeral lateral condyle fracture (HLCF) in different positions of the forearm based on human cadaveric HLCF models.MethodsThree human cadaveric elbow HLCF fracture models were successfully established. The wrist joint was fixed, and the forearm was rotated forward along the mid‐axis. The maximum distance between the two segments of the lateral fracture gap was defined as LFS (lateral fracture space) distance, and the maximum distance between the two segments of the fracture gap at the anterior and posterior margins of the fracture model was defined as PFS (posterior fracture space). The LFS and PFS distances of the human cadaveric elbow HLCF fracture models were measured during forearm rotation at 0º, 45º, 90º, and 135º rotation using a Capture Motion System (CMS), positive and lateral elbow X‐ray, coronal and sagittal MRI scans, respectively, and the CMS measurements were considered as the true fracture gap distances. The values obtained by CMS, X‐ray, and MRI measurements for both LPS and PFS distances in the HLCF fracture model at each position during rotation were recorded. The LFS and PFS distances were measured by two independent orthopaedic and joint imaging physicians. The data were measured three times by each physician, and the final values were the average of the two measurements. The outcomes were determined by whether a statistical difference exists in the LFS and PFS among the CMS, X‐ray, and MRI groups.ResultsThe interobserver agreement tests between the two observers showed good agreement in the measurements. A multiple sample ANOVA showed statistical differences in the LFS distances of HLCF measured at 0º, 45º, 90º, and 135º rotated by three radiographic measurements (P < 0.05). The LFS distances obtained by MRI and CMS measurements were greater than those obtained by X‐ray measurement in all positions using the LSD test (P < 0.05), and no statistical difference was found between the CMS and MRI methods in each position (P > 0.05). The same results were observed in terms of PFS values obtained by CMS, X‐ray, and MRI measurements at 0º, 45º, 90º, and 135º pronation. It was statistically different among the three groups as shown by multiple sample ANOVA (P < 0.05). The CMS and MRI measurements were greater than the X‐ray measurements (P < 0.05), while no statistical difference was observed between the CMS and MRI measurements (P > 0.05).ConclusionX‐rays often underestimate the degree of displacement of HLCF fractures; MRI measurements are closer to the true values compared with X‐ray.

Hydrokinetic turbine array analysis and optimization integrating blockage effects and turbine-wake interactions

In order to maximize the energy extraction of a hydrokinetic turbine array deployment, turbines must be positioned judiciously within the array. In fact, it is possible to optimize the array configuration in order to benefit from blockage effects and to avoid negative turbine-wake interactions. The Effective Performance Turbine Model (EPTM) that has recently been proposed is a suitable tool for this purpose, allowing to test and analyze a large number of different configurations at a practical computational cost. In this work, assuming a turbulent flow environment, many vertical-axis turbine array configurations (VAT arrays) are tested to study the effect of local blockage, lateral and longitudinal spacing, array staggering and direction of rotation on turbine performance. It is found that the wake deflection associated to the specific turbine tested and the lateral force it induces has a great impact on the array optimization. Following this, results show that there is no advantage to stagger VATs and that aligned configurations should be preferred. In this context, turbines should rotate inward (looking downstream) with respect to the central plane of the array. Some guidelines are also provided in terms of lateral and longitudinal spacings, with the support of a novel parameter indicating the marginal power provided by the addition of a row of turbines.

Migrated fish bone into the neck: a case report

BackgroundImpaction of foreign body is a common condition presented to ear, nose, and throat department among Asian population. The commonest foreign body seen among this population has been documented as fish bone. Fish bone can migrate to lateral neck space or related organs around the neck and chest. By presenting this case report, we aim to emphasize the importance of taking proper history and make clinicians aware of the possibility of a fish bone migrating into different spaces. This will help to prevent diagnosis delay leading to complications due to migrated fish bone.Case presentationA 50-year-old female Sinhalese patient presented to ear, nose, and throat department with right-sided neck pain for 2 days, who had a history of suspected fish bone impaction a few days ago that subsided without any investigations or treatments. She did not have any symptoms related to throat, and neck examination showed mild swelling and tenderness. Computer tomography revealed a migrated fish bone into the lateral neck close to carotid artery, and the fish bone was removed by neck exploration under general anesthesia without any complications.ConclusionIn conclusion, migrated fish bone should be suspected if patient is having persistent symptoms mainly in the neck without having difficulty swallowing and who gives a history of fish bone impaction and having negative laryngoscopic examination. Proper history taking is very important in the assessment of these patients to prevent misdiagnosis of the condition. Clinicians should aware that migrated fish bones are not uncommon and that early suspicion can prevent later diagnosis and complications.

Determination of the Optimal Syndesmosis Fixation Angle Using the Mortise View of the Ankle Joint.

Syndesmosis is an important soft-tissue component supporting ankle stability. It is commonly injured along with ankle fractures. Accurate reduction and fixation of syndesmosis is essential to obtain better functional results. Therefore, we aimed to find a practical method using the mortise view of the ankle to determine the optimal syndesmosis fixation angle intraoperatively. We randomly selected 200 adults (100 women and 100 men) aged 18 to 60 years. Three-dimensional anatomical models of the tibia and fibula were created. We created a best-fit plane on the articular surface of the medial malleolus and a 90° vertical plane to the medial malleolus plane. We determined two splines on the cortical borders of the tibia and fibula distant from the most superior point of the ankle joint in horizontal view. We created two spheres that fit to the predefined splines. The optimal syndesmosis fixation angle was determined measuring the angle between the line connecting the center points of the spheres and the 90° vertical plane to the medial malleolus plane. We observed no statistically significant difference in optimal syndesmosis fixation angles between sex groups. The participant mean ± SD age was 47.1 ± 10.5 years. The optimal syndesmosis fixation angle in the mortise view was found to be 21° ± 4.3°. We determined the optimal syndesmosis fixation angle to be 21° ± 4.3° using the mortise view of the ankle. The surgeon could evaluate the whole articular surface of the ankle joint with the medial and lateral syndesmotic spaces in mortise view accurately, and at the same position syndesmosis fixation could be performed at a mean ± SD angle of 21° ± 4.3°.